The popularity of electronic messaging such as e-mail is being marred by ever increasing amount of unsolicited messages (commonly known as “spam”) that is received by users. Spam can waste users' time, can clog users' electronic storage devices, and its shear volume can make it difficult for a user to identify messages that the user wants receive. In the process of deleting spam, a user can inadvertently delete wanted messages. Spam can contain advertisements (e.g., such as Unsolicited Commercial E-Mail (“UCE”)); deceptive and/or unlawful offers; viruses; spyware; offensive content; and other undesirable forms of information. Vast numbers of spam messages can be sent for little or no cost to their sender (“spammer”), who can take various actions to hide his true identity. For example, spammers often forge the source address of the e-mails that they send. Spam can be received in practically any medium, including e-mail, instant messaging, telephonically, etc. Practically any arena in which a party may initiate an unsolicited communication may be exploited by spammers. For example, automated and live unsolicited telephone calls is a well known technology exploited by certain spammers (e.g., telemarketers.)
Legislative measures for controlling spam have largely been stymied by constitutional concerns relating to freedom of speech. Further, it can be as easy to send spam from abroad as from a jurisdiction in which spam is controlled by law.
Blacklisting e-mails with various predetermined characteristics (e.g., from a given address, containing certain keywords, etc.) has been less than totally effective because spammers have learned to change the content and source addresses to circumvent blacklists. Further, a blacklist can also inadvertently stop wanted messages from being seen by a user, which is undesirable.
A new solution is needed to accurately and effectively solve the problems caused by spam.